The role of the Biostatistics Core Component (BCC) of the program project grant is to serve as a centralized resource to the investigators of the Hematology/BMT program project, to provide data management services and biostatistical consultation as needed. The specific aims of the BCC are: 1. To assist in the planning and study design of the projects of the grant, including sample size projections, randomization and statistical methods 2. To provide protocol management for the clinical studies of the program project 3. To provide data management and computerization for the clinical studies of the program project 4. To perform quality control assurance of the data collection and computerization, including routine audits of in-house protocol data 5. To perform statistical analysis of the study results, and collaborate in the writing of manuscripts The BCC staff will consist of the Principal Investigator, Ph.D. Biostatistician, Biostatistics Core Manager, and three Data Managers. Mechanisms are currently in place for providing randomization, study design and protocol review, protocol and data management, audits of in-house protocols, and answering data requests. Statistical analyses will be performed using the SAS and BMDP software packages. Computer resources are available to the BCC via a local area network of personal computers within the Department of Biostatistics, as well as links to the mainframe computers in the Data Processing Department. A clinical trials software program (the Protocol Tracking and Information System--PTIS) has been developed in-house, and currently contains over 1000 records of data on bone marrow transplant patients.